The invention generally relates to colloidal light valves. More particularly, this invention relates to colloidal light valve material which has frequency dependent light transmission characteristics. Specifically, this invention relates to a system for multiplex addressing an array made up of colloidal light valves exhibiting this frequency dependent trait.
Colloidal light valve (CLV) materials per se have been known for many years. See, for example, U.S. Pat. Nos. 1,955,923 and 1,963,496. However, their usefulness in displays has been limited because they were not particularly suited to multiplex addressing. This was so because CLV materials did not exhibit a sharp voltage or frequency threshold as did for example, liquid crystals. We have developed at least two CLV materials which exhibit sharp frequency thresholds and have successful made arrays, using these materials, which can be multiplex addressed. The operation of these CLV materials is therefore a function of both the potential difference across a cell fitted with such material and the frequency of the applied signal.
The following prior art references are considered to be pertinent:
A. M. Marks, "Electrooptical Characteristics of Dipole Suspensions", Applied Optics, vol. 8, pp. 1397-1414, July, 1969.
A. M. Marks, "Electrooptical Properties of Dipole Fluids and Their Applications to Displays", Publication of Marks Polarized Corporation, Whitestone, New York.
E. Gordon and L. Anderson, "New Display Technologies--An Editorial Viewpoint", Proceedings of the IEEE, Vol. 61, No. 7, pp. 807-813, July, 1973.
L. A. Goodman, "Liquid Crystal Displays Electro-Optic Effects and Addressing Techniques", RCA Review, Vol. 35, No. 4, pp. 613-651, December, 1974.
C. Stein and R. Kashonow, "A Two-Frequency Coincidence Addressing Scheme for Nematic-Liquid-Crystal Displays", Applied Physics Letters, Vol. 19, No. 9, pp. 343-345, November, 1971.
S. P. Stoylov, "Colloid Electro-Optics-Electrically Induced Optical Phenomena in Disperse Systems", Advances in Colloid and Interface Science, No. 3, pp. 45-110, 1971.
P. Wild and J. Nehring, "Turn-On Time Reduction and Contrast Enhancement in Matrix Addressed Liquid-Crystal Light Valves", Applied Physics Letters, Vol. 19, No. 9, pp. 335-336, November, 1971.
U.S. Pat. Nos. 3,841,732; 3,512,876; 3,773,684; 3,885,861; 3,878,537; and 3,895,373.